Table of Contents

This document contains the aggregated coding from BQA Memos
90.03, 92.01 and 95.01 to use for storing QC samples in NWIS-I.

Definitions of Quality-Assurance DataBlank samples are taken to ensure that environmental samples have
not been contaminated by the data-collection process. Any
measured value/signal in a blank sample for an analyte (a
specific component measured in a chemical analysis) that was
absent in the blank solution is believed to be due to
contamination. There are many types of blank samples possible,
each designed to segregate a different part of the complete data-
collection process including sampling, filtering, preserving,
storing, transporting, and analyzing:Blank solution - Solution that is free of the analyte(s) of
interest. Such a solution would be used to develop specific types
of blank samples as described below.Ambient blank - a blank solution that is put in the same type of
bottle used for an environmental sample, kept with the set of
sample bottles before sample collection, and opened at the site
and exposed to the ambient conditions.Equipment blank - a blank solution that is processed through all
equipment used for collecting and processing an environmental
sample (similar to a field blank but normally done in the more
controlled conditions of the office and not being transported to
the field).Field blank - a blank solution that is subjected to all aspects
of sample collection, field processing, preservation,
transportation, and laboratory handling as an environmental
sample.Filter blank - a blank solution that is filtered in the same
manner and through the same filter apparatus used for an
environmental sample.Lab blank - a blank solution prepared in the laboratory and
analyzed the same as an environmental sample.Preservation blank - a blank solution that is treated with the
same preservatives used for an environmental sample.Refrigerator blank - a blank solution that is put in the same
type of bottle used for an environmental sample and stored
adjacent to an environmental sample in a refrigerated storage
area.Sampler blank - a blank solution that is poured or pumped through
the same field sampler used for the collection of an
environmental sample.Shelf (or hold) blank - a blank solution that is put in the same
type of bottle used for an environmental sample and stored
adjacent to an environmental sample in a storage area.Splitter blank - a blank solution that is mixed and separated
using a field splitter in the same manner and through the same
apparatus used for an environmental sample.Source solution blank - a blank solution sent to a laboratory to
confirm that it is free of the analyte of interest.Trip blank - a blank solution that is put in the same type of
bottle used for an environmental sample and kept with the set of
sample bottles both before and after sample collection.Blind sample - A sample submitted for analysis whose composition
is known to the submitter but unknown to the analyst. A double
blind sample is one of known composition that is submitted to the
analyst in such a manner that neither its composition nor its
identification as a check sample is known to the latter. A blind
sample is one way to test the proficiency of a measurement
process. Blind samples can be used to monitor the performance of
an analytical system, check the analytical results of more than
one laboratory, more than one analytical method, or the
consistency of the same laboratory and method. Every blind sample
analyzed should have an associated reference to the source and
the possible dilution. Blind samples may be prepared from a
reference material, as defined below.Reference material - A material or substance one or more
properties of which are sufficiently well established to be used
for the assessment of a measurement method or for assigning
values to materials.Replicate (Duplicate) samples - A group of samples, collected in
a manner such that the samples are thought to be essentially
identical in composition. Replicate is the general case for which
duplicate is the special case consisting of two samples. There
are many types of replicate samples possible, each of which may
yield slightly different results in a dynamic hydrologic setting,
such as a flowing stream. The types of replicate samples are:Concurrent samples - samples collected by two or more people
collecting samples simultaneously, or by one person alternating
subsamples between two or more collection bottles.Sequential sample - a type of replicate sample in which the
samples are collected one after the other, typically over a short
period of time.Split sample - a type of replicate sample in which a sample is
split into subsamples contemporaneous in time and space.Spike sample - A sample to which known concentrations of specific
analytes have been added in such a manner as to minimize the
change in the matrix of the original sample. Every spiked sample
analyzed should have an associated reference to the spike
solution and the volume added.Spike solution - A solution with one or more well established
analyte concentrations that is added in known quantities to an
environmental sample to form a spike sample.Identification of Quality-Assurance Data in NWIS________________________________________________A system for identifying quality-assurance samples and
maintaining the relationship with corresponding environmental
samples has been established. The MEDIUM CODE, DATE, TIME and
SAMPLE TYPE are used in the following manner to identify clearly
all QA data:Blank -(1) Use actual STATION NUMBER, DATE and TIME for blanks
associated with a specific site and environmental sample. Use
artificial STATION NUMBER, DATE and TIME for blanks that are
associated with many sites and/or environmental samples. If more
than one blank is analyzed, increment the TIME by 1 minute for
each blank.(2) Use a MEDIUM CODE of Q (new code).(3) Use a SAMPLE TYPE of 2 (new code).(4) Use new parameter codes to designate which type of blank
solution, the source of the blank solution, and the type of blank
sample.(5) If more than one blank is collected, use parameters 82073 and
82074 to enter the same STARTING TIME and ENDING TIME for each
blank.Blind -(1) Use actual STATION NUMBER, DATE and TIME for blinds
associated with a specific site and environmental sample. Use
artificial STATION NUMBER, DATE and TIME for blinds associated
with many sites and/or environmental samples. If more than one
blind is analyzed, increment the TIME by 1 minute for each blind.(2) Use a MEDIUM CODE from Q-Z (new codes).(3) Use a SAMPLE TYPE of 4 (new code).(4) Use new parameter codes to designate the source of the
reference material and the source code number.(5) If more than one blind is collected, use parameters 82073 and
82074 to enter the same STARTING TIME and ENDING TIME for each
blind.Reference Material -(1) Assign an artificial STATION NUMBER.(2) Use the DATE and TIME that material was created or received.(3) Select a MEDIUM CODE from Q-Z (new codes).(4) Use a SAMPLE TYPE of 6 (new code).(5) Use new parameter codes to designate the source of the
reference material and the source code number.Replicate -(1) Use the existing STATION NUMBER.(2) Use actual DATE and TIME for the 1st sample and increment
TIME by 1 minute (or actual times if greater than 1 minute) for
each additional sample.(3) Select a MEDIUM CODE from Q-Z (new codes).*(4) Use a SAMPLE TYPE of 7 for every sample, including the first
one.(5) Use a new parameter code for replicates to designate which of
the methods was used to create the replicates.(6) Use the same STARTING TIME and ENDING TIME (parameters 82073
and 82074) for all samples.* If the replicate samples will be stored in the regular data
base, use normal MEDIUM CODES (i.e., 6 or 9) and a sample type of
7.Spike -(1) Use actual STATION NUMBER, DATE and TIME for spikes
associated with a specific site and environmental sample. Use
artificial STATION NUMBER, DATE and TIME for spikes that are
associated with many sites and/or environmental samples. If more
than one spike is analyzed, increment the TIME by 1 minute for
each spike.(2) Select a MEDIUM CODE from Q-Z (new codes).(3) Use a SAMPLE TYPE of 1.(4) Use new parameter codes to designate the source code number
of the spike solution, the spike type, and the volume of the
spike. Use an existing code (32000) to designate the sample
volume.(5) If more than one spike is collected, use parameters 82073 and
82074 to enter the same STARTING TIME and ENDING TIME for each
spike.Spike Solution -(1) Assign an artificial STATION NUMBER.(2) Use the DATE and TIME that source was created or received.(3) Use a MEDIUM CODE of Q (new code).(4) Use a SAMPLE TYPE of 8 (new code).(5)Use new parameter codes to designate the source of the spike
solution and the source code number of the spike solution.A DISTRICT PROCESSING STATUS code of Z (local use only) should be
assigned to each QA sample to prevent the data from being
transferred to the national data base and subsequently to the
EPA's STORET data base.New Codes_________Medium CodesQ Quality-Assurance Sample -- ArtificialR Quality-Assurance Sample -- Surface WaterS Quality-Assurance Sample -- Ground WaterT Quality-Assurance Sample -- Wet DepositionU Quality-Assurance Sample -- Bulk DepositionV Quality-Assurance Sample -- Suspended SedimentW Quality-Assurance Sample -- Bottom MaterialX Quality-Assurance Sample -- Animal TissueY Quality-Assurance Sample -- Plant TissueZ Quality-Assurance Sample -- Interstitial WaterSample Types 1 *Spike 2 Blank 3 *Reference 4 Blind5 *Duplicate6 Reference Material7 *Replicate8 Spike SolutionB Other Quality Assurance* Existing sample types that apply to quality assurance dataRemark CodesA Average valueV VarianceS Most probable valueParameter Codes99100 Blank, Type of solution (fixed value)10.00 Distilled/deionized Water20.00 Standard Reference Water Sample30.00 Matched Matrix40.00 Organic-free water50.00 VOC free water200.00 Other99101 Blank, Source of solution (fixed value)10.00 National Water Quality Lab20.00 U.S. Environmental Protection Agency30.00 Standard Reference Water Sample (USGS)35.00 Mix of Standard Reference Water Samples40.00 NIST (formerly NBS)50.00 Canadian Inland Waters60.00 District lab61.00 Subdistrict #1 Lab62.00 Subdistrict #2 Lab63.00 Subdistrict #3 Lab64.00 Subdistrict #4 Lab70.00 Natural sample71.00 Field Office #1 Lab72.00 Field Office #2 Lab73.00 Field Office #3 Lab74.00 Field Office #4 Lab80.00 Ocala Lab99.99 Unknown100.00 Chemical Supplier110.00 Burdick And Jackson120.00 J.T. Baker200.00 Other99102 Blank, Type of sample (fixed value)1.00 Source Solution10.00 Shelf (hold)20.00 Refrigerator30.00 Trip40.00 Sampler50.00 Splitter60.00 Filter70.00 Preservation 80.00 Equipment90.00 Ambient100.00 Field150.00 Lab Blank200.00 Other99103 Reference Material, Source (fixed value)10.00 National Water Quality Lab20.00 U.S. Environmental Protection Agency30.00 Standard Reference Water Sample (USGS)35.00 Mix of Standard Reference Water Samples40.00 NIST (formerly NBS)50.00 Canadian Inland Waters60.00 District lab70.00 Natural sample80.00 Ocala Lab99.99 Unknown100.00 Chemical Supplier200.00 Other99104 Reference Material or Spike Source, Code Number99105 Replicate, Type (fixed value)10.00 Concurrent20.00 Sequential30.00 Split40.00 Split-concurrent50.00 Split-sequential200.00 Other99106 Spike, Type (fixed value)10.00 Field20.00 Laboratory30.00 Surrogate40.00 Internal Standards200.00 Other99107 Spike, Source (fixed value)10.00 National Water Quality Lab20.00 U.S. Environmental Protection Agency30.00 Standard Reference Water Sample (USGS)35.00 Mix of Standard Reference Water Samples40.00 NIST (formerly NBS)50.00 Canadian Inland Waters60.00 District lab70.00 Natural sample80.00 Ocala Lab99.99 Unknown100.00 Chemical Supplier200.00 Other99108 Spike Volume99109 Starting date for a set of samples (YMMDD)99110 Ending date for a set of samples (YMMDD)99111 Quality assurance data type associated with sample, fixed
value code1.00 No associated qa data10.00 Blank20.00 Blind Sample30.00 Replicate Sample40.00 Spike Sample100.00 More than one type of QA sample110.00 Cross-section information stored200.00 Other